Dishwasher door and counterbalance apparatus



June 22, 1965 w, s 3,190,711

DISHWASHER DOOR AND COUNTERBALANCE APPARATUS Filed Oct. 22, 1962 :s Sheets-Sheet 1 x. 1 H u INVENTOR. ARTHUR W. HAAS A. w. HAAS' 3,190,711 R AND COUNTERB NOE APPARATUS FiledOct. 22. 1962 3 Sheets-Sheet 2 June 22, 1965 A. w. HAAS DiSHWASI-IER DOOR AND COUNTERBALANCE APPARATUS Filed Oct. 22, 1962 3 Sheets-Sheet 3 ARTHUR w HAAS I 3 T/ORNEYS 3, l 90 ,7 l l Patented June 22, 1965 3,190,711 DISHWASHER DOOR AND COUNTERBALAN CE APPARATUS Arthur W. Haas, Rochester, N.Y., assiguor to Toledo Scale Corporation, Toledo, Ohio, a corporation of Ohio Filed Oct. 22, 1962, Ser. No. 232,164 11 Claims. (Cl. 312284) This invention relates to dishwashing machines and more particularly to improved doors and door operating means for such machines.

In commercial type dishwashing machines such as are used in restaurants, etc., it is customary to employ counterweights to assist in raising and lowering the doors. In the usual machine, such as shown in US. Patent No. 2,633,399, issued March 31, 1953 to A. W. Haas, the counterweight is operatively connected to a door by means of a single cable which is attached to the door at two places. This prior door and door operating means are generally unsatisfactory in that close tolerances were used in obtaining a free moving door and in obtaining a good seal at the top of the door to keep in steam and Water, and no adjustment means was provided to obtain such free movement and good seal easily. At best relatively high friction was present between the door and its guide means which are shown in US Patent No. 2,719,070, issued September 27, 1955 to A. W. Haas. Also, the doors shown in the above patents were not rigid enough to Withstand abuse without losing their adjustments.

Accordingly, the objects of this invention are. toimprove the counterweight systems which assist in raising and lowering the doors in dishwashing machines,'to provide adjustment means to assist in making such doors free moving and to align such doors to seal in steam and water when the doors are closed, to reduce-friction between .such doors and their guide means, to simplify the construction and assembly of such doors and their door operating means, to make such doors more convenient for the operators to use, and to provide stiffer, stronger doors which can withstand abuse and that keep freemoving during extensive use.

, One embodiment of this invention enabling the realization of these objects is a four-point suspension door which is operatively connected to a counterweight, that assists in raising and lowering the door, by means of two cables one of which is connected to one side of the door at two places and the other of which is connected to the opposite side of the door at two places. The four: point suspension permits a sloppy fit to be used between the door bottom and its guide means so that friction is reduced and manufacturing tolerances can-be relaxed. The cables are connected to novel door stiffeners that run about the length of the door bottom and are connected to, the counterweight by means of novel cablelength adjustment devices. v v i in accordance with the above, one feature of this invention resides in the four-point suspension of the door which provides a really freemoving door and one which is easy to adjust relative to the roof of the dishwashing machine to obtain a good seal.

Another feature resides'in the design of the door stiiieners which are of simple construction yet add greatly to the rigidity of the door.

Still another feature resides in the adjustment device by means of which the door easily is made free moving and by means of which the door is aligned with the roof of the machine to form a good seal. This greatly facilitates assembly. I The above and other objects and features of this invention will be appreciated more fully from the following detailed description when read with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of a dishwashing machine embodying the invention;

FIG. 2 is an enlarged, horizontal sectional view taken along the line 2-2 of FIG. 3;

FIG. 3 is a perspective View of the machine shown in FIG. 1 taken from a diiferent angle and showing the door in open position;

F-IG. 4 is an enlarged, vertical sectional View taken along the line 4 4 of FIG. 5;

, FIG. 5 is an enlarged view of the upper part of the machine as shown in FIG. 3 with parts broken away to to show interior details;

FIG. 6 is an enlarged, fragmentary view of a lower part of the door as seen in FIG. 5;

FIG. 7 is an enlarged, vertical sectional view taken along the line 7-7 of FIG. 6; and

:FIG. 8 is an enlarged, exploded view of the fragment of the device shown in FIG. 6. I

Referring to the drawings, a dish-washing machine embodying the invention includes a frame '10 having a washing and rinsing space enclosed by a vertically movable three-sided door 11. The invention concerns improved door and door operating means and it is to be understood that the three-sided door is shown as an example =only, the invention having utility in connection with doors having other numbers of sides, such as a one-sided door.

The frame d0 encloses a tank containing washing solution which is sprayed onto dishes placed in the washing and rinsing space above the tank through slotted wash spray tubes such as are shown in US. Patent No. 2,786,478, issued March 26, 1957 to B. E. Robinson and R. .0. Bradley. The washing solution from the tank returns to a motor-driven pump '12 which forces the washing solution through thespray tubes. "Additional rinse spray tubes, as also disclosed in the above US. Patent No. 2,786,478, are provided above and below the washing and rinsing space to supply hot rinse liquid from a fresh water supply directly onto the dishes for rinsing and sterilizing the dishes. Control of the rinsing operation is accomplished by an electrically-operated solenoid valve 13. Operation of the washing and rinsing devices is effected by pushing a wash button 14 and a rinse button 15 mounted on a control box 16 located at the right hand side of the frame '10.

The door 1 1 is raised or lowered, respectively, by an operator grasping a handle 17 and sliding the door up until a stop 18 on the door engages the bottom of a roof 19, supported by a rear wall 20, two rear channels 21 and two front posts 22, and sliding the door down until a horizontal rim or edge 23 around the top of the three sides of the door-11 engages the top of the roof 19. Engagement of the door rim 23 with the edges of the roof 1'9 seals in steam and water. The door 11 has its two rearward vertical edges guided in the channels 21 and its two forward corners guided by the posts 22 which are L-shapedin cross section. V

.The door 11 comprises a front wall and a pair of side walls extending at right angles from the front Wall. When the door 11 is operatively assembled on the ma-, chine, the interior corners of the door formed by the front wall and the side walls correspond with the corners of the L-shaped posts 22 and are in juxtaposition therewith. Fixed to the inner side of the front wall ,of

the door 11 adjacent the respective corners is a pair of I vertical channels 24 which are generally U-shaped in cross-section. One of the channels 24 is shown in FIG. 2, there being one channel 24 at each front corner of the door 11. The channels 24 substantially encompass the adjacent legs of the L-shaped posts 22 which have front portions generally parallel to the front Wall of the door 11 and are of a length generally equal to the height of the door 11.

At the upper end of each post 22 is a pair of oppositely directed slide buttons 25 which are adapted to slidingly engage the inner sides of the channels 24 during up and down movement of the door 11. The slide buttons 25 have edges extending beyond the ends of the legs of the posts 22 to which they are attached for the purpose of limiting lateral movement of the door 11 by engagement with the bottoms of the channels 24. Since there are no guide buttons carried by the bottom of the door 11, the bottom of the door 11 in most positions has a sloppy fit reducing the close tolerances used in prior dishwashing machines and reducing the friction encountered in prior dishwashing machines. This sloppy fit is tolerated by the four-point suspension for the door hereinafter described and is exploited in aligning the door rim 23 with the edges of the roof 19 to form a good seal also as hereinafter describe-d. The door guide means shown in FIG. 2 is like the door guide means shown in the above U.S. Patent No. 2,719,070, except that the guide buttons shown in the patent which are carried by the lower part of the door are omitted in the present construction.

A hollow elongated stiffener member 26 is carried by each of the side walls of the door 11 at the bottom of the door for the purpose of adding to the rigidity of the door, the stiffeners running about the length of the side walls. Nuts 27 and bolts 28 attach the stiffeners 26 to the door 11. The bottoms of the side walls of the door 11 are turned up in rounded edges 29 which receive correspondingly shaped rounded bottom portions of the stitfeners 26 each of which has a vertical surface 30 butted against the vertical inner wall of its respective door wall. Each of the stiifeners 26 also has a horizontal extended surface 31 and a surface 32 sloping upwardly from such horizontal surface toward its respective door wall for purposes hereinafter described.

A counterweight 33 is provided to assist-in raising and lowering the door. The counterweight is connected to the door 11 by means of two lines or cables 34 each of which is attached to the door at two places by means of connectors 35 to suspend the door at four points. The counterweight 33 is attached to a horizontal channel 36 having downwardly extending legs and a slot 37 in each of its ends which respectively receive flanges 33 on the vertical channels 21 to guide the counterweight in its vertical path. Referring to FIG. 5, a single pulley 39 is rotatably mounted by means of a bracket 40 depending from the roof 19 and a double pulley 41 is rotatably mounted by means of a bracket 42 depending from the roof 19, the pulleys being located generally in the respective left hand corners of the machine as viewed in FIG. near the roof. Identical pulleys (not shown) in an identical arrangement are similarly located in the respective right hand corners of the machine as viewed in FIG. 5.

Both of the cables 34 are shown in FIG. 5, but the right hand one is not completely shown nor are the pulleys and cable connectors shown for such right hand cable because the two cable systems are identical. In the complete cable system shown in FIG. 5, the cable 34 runs from one of the cable connectors 35 up to and around the single pulley 39, horizontally to and around a first groove in the double pulley 41, down to and around a round rod 43 carried by and extending between the legs of the horizontal channel 36, up to and around a second groove in the double pulley 41, and down to the other one of the cable connectors 35. Each of the cables 34 is anchored at its rod 43 by means of a triangularly shaped lock plate 44 having notched legs 45 for reception of the cable and a screw 46 (see FIG. 4) which extends vertically through the apex of the triangle and the channel 36 and into mating threads in the rod 43. This suspends the door at four points. The door is nicely balanced and is freely movable from its position shown in FIG. 5 down to its closed position shown in FIG. 1 to lift the counterweight to a position near the roof 19. The four-point suspension allows the door 11 to move vertically in either direction without binding, and the above described sloppy fit of the door at its bottom reduces friction to aid in the free movement of the door. A door suspended at only two points such as shown in the above U.S. Patent No. 2,633,399 tends to pivot about such point when a moment is applied to the door through its handle. A door suspended at four points, one of the features of the present machine, is stable and is movable without binding.

Each of the four cable connectors includes a flat plate 47 welded to the horizontal surface 31 of the respective stiffener 26 and a plate 43 shaped as shown in FIG. 7 engaging the upper surface of the flat plate 47 and the sloping surface 32 of the stiffener 26 and held in such engagements by one of the nuts 27 and bolts 28, such nut and bolt serving to both attach the stiffener to the door and'the plate 48 to the stiffener. As shown in FIG. 8, the plates 47 and 48 have oppositely directed open-ended slots 49 and 50, respectively. Each of the four ends of the two cables carries a steel ball 51 securely fixed thereto. In attaching the respective cable end to the door 11, the steel ball is positioned underneath the plate 47 with the cable 34 received in the slot 49 as shown in FIG. 3, the plate 48 is positioned as shown in FIG. 8 with the cable received in the slot 53, and then the plate 43 is bolted to the stiffener 26. This locates the plate 48 as shown in FIGS. 6 and 7 with the cable 34 clamped in the bottoms of the two slots 49 and 5t and securely holds the cable ends in place.

Another one of the features resides in the adjustment of the door when assembling the machine to get a free moving door and to align the door rim 23 with the edges of the roof 19 to form a good seal to keep in steam and water. In prior machines, the doors are aligned by bending by means of brute force. The lock plates 44 and their adjuncts serve as adjustment means for the door -11. As shown in FIG. 5 there is one of such adjustment means at the channel 36 for each of the cables 34. One of the adjustment means is shown in detail in FIG. 4. The screw 46 tends to flatten the triangularly shaped lock plate 44 forcing the notched legs apart until they anchor the cable 34 in two places to the top of the channel 43. In making the adjustment, one of the screws 46 is loosened and the respective cable 34 is moved through holes 52 in the channel 36 around the rod 43 to vary the cable lengths between the respective cable connectors 35 and the respective lock plate 44. This tilts the particular door side wall to which such cable connectors are connected about a generally horizontal axis. The screw 46 is retightened and the procedure is repeated with the other adjustment means and then possibly repeated again back and forth by trial and error until the door runs easily and the door rim 23 is aligned with the edges of the roof 19 to form a good seal. This greatly facilitates assembly. Furthermore, the adjustment once made is held securely, the notched legs 45 biting into the cables 34 with enough force to securely anchor them in place.

It is to be understood that the above description is illustrative of this invention and that various modifications thereof can be utilized without departing from its spirit and scope.

Having described the invention, I claim:

1. In a dishwashing machine, in combination, means defining a washing and rinsing space, a door for enclosing a portion of the space, means for guiding the door as it is moved with respect to the space to and from a closed position, a counterweight for assisting in raising and lowering the door, two continuous cables each having its ends anchored to the door and an intermediate portion anchored to the counterweight to operatively connect the door to the counterweight, and a pulley system for each of the cables.

2. A dishwashing machine according to claim 1 wherein each of the pulley systems includes a single and a double pulley, the pulleys being located between an end of the respective cable and the counterweight and the double pulley being located between the other end of such cable and the counterweight.

3. A dishwashing machine according to claim 1 wherein each of the cable ends is anchored to the door by a connector including two members having oppositely directed open-ended slots, the cable end being clamped in the bottoms of the slots.

4. A dishwashing machine according to claim 1 wherein each of the cable ends is anchored to hollow, elongated stifiener means carried by the door.

5. A dishwashing machine according to claim 1 wherein each of the intermediate cable portions is anchored to the counterweight by an adjustment device including a triangularly shaped lock plate having notched legs for reception of the cable and a screw extending through the apex of the triangle to deform the lock plate and thus clamp the cable between the lock plate legs and the counterWei-giht.

.6. In a dishwashing machine, in combination, means defining a washing and rinsing space, door means having two parallel sides for enclosing a portion of the space, guide means for guiding the door means as it is moved to and from a closed position, a counterweight for assisting in raising and lowering the door means, two continuous cables one having its ends anchored to one of the parallel sides and the other having its ends anchored to the other parallel side and each cable having an intermediate portion anchored to the counterweight to operatively connect the door means to the counterweight and a pulley system for each of the cables.

7. A dishwashing machine according to claim 6 Wherein the bottom of the door means has a loose fit with the guide means when in closed position and each of the intermediate cable portions is anchored to the counterweight by adjustment means for tilting the respective parallel side until the door means is freely movable.

8. In a dishwashing machine, in combination, means defining a washing and rinsing space and including a stationary roof closing the space at the top, door means having two parallel sides for enclosing a portion of the space, each parallel side having a rim engageable with the roof for sealing in steam and Water, guide means for guiding the door means as it is moved to and from a closed position, the guide means having a loose fit with the bottom of the door means when the door means is closed, a counterweight for assisting in raising and lowering the door means, two continuous cables one having its ends anchored .to one of the parallel sides and the other having its ends anchored to the other parallel side and each cable having an intermediate portion anchored to the counterweight to operatively connect the door means to the counterweight, and a pulley system for each of the cables, the intermediate cable portions being anchored to the counterweight by adjustment means for tilting the respective parallel side to align the respective rim with the roof whereby a good seal is formed between the rim and the roof when the door means is closed.

9. A dishwashing machine according to claim 8 Wherein each of the pulley systems includes a single and a double pulley depending from the roof, the pulleys being located between an end of the respective cable and the counterweight and the double pulley being located between the other end of such cable and the counterweight.

10. In a dishwashing machine, in combination, means defining a washing and rinsing space and including a stationary roof closing the space at the top, a door having a front wall and a pair of side walls extending at right angles from the front wall for enclosing the space on three sides, each door wall having a rim cngageable with the roof for scaling in steam and water, guide rneans for guiding the door as it is moved to and from a closed position, the guide means having a loose =fit with the "bottom of the door when the door is closed, a counterweight for assisting in raising and lowering the door, two continuous cables one having its ends anchored to one of the door side Walls and the other having its ends anchored to the other .of the door side walls and each cable having an intermediate portion anchored to the counterweight to operatively connect the door to the counterweight, and a pulley system tor each of the cables, the intermediate cable portions being anchored to the counterweight by adjustment means for tilting the door side walls about a generally horizontal axis to align the rims with the roof, each of the pulley systems including a single and a double pulley depending from the roof, the pulleys being located between an end of the respective cable and the counterweight and the double pulley being located between the other end of such cable and the counterweight.

1 1. In a dishwashing machine, in combination, a door tor enclosing a portion of a Washing and rinsing space, guide means for guiding the door as it is moved to and from closed positions, the guide means having a loose fit with the bottom of the door when the door is closed, a tour point suspension system for the door, and adjustment means for tilting the door relative to the guide means until the door is freely movable.

References Cited by the Examiner v UNITED STATES PATENTS FRANK B. SHERRY, Primary Examiner, 

1. IN A DISHWASHING MACHINE, IN COMBINATION, MEANS DEFINING A WASHING AND RISING SPACE, A DOOR FOR ENCLOSING A PORTION OF THE SPACE, MEANS FOR GUIDING THE DOOR AS IT IS MOVED WITH RESPECT TO THE SPACE TO AND FROM A CLOSED POSITION, A COUNTERWEIGHT FOR ASSISTING IN RAISING AND LOWERING THE DOOR, TWO CONTINUOUS CABLES EACH HAVING ITS ENDS ANCHORED TO THE DOOR AND AN INTERMEDIATE PORTION ANCHORED TO THE COUNTERWEIGHT TO OPERATIVELY CONNECT THE DOOR TO THE COUNTERWEIGHT, AND A PULLEY SYSTEM FOR EACH OF THE CABLES. 